it probably is effective by warning the parents and showing the signs of a predator and how far they will go.
It also prevents the guys they caught from hooking up with the real thing.
Its like the police stings where they pose as hitmen for hire. When they catch a guy, it represents a life saved.
I have seen many TV news docs that highlighted the problem without resorting to staged stings.
And once morem I totally support the police doing this off camera, so they can identify these people and offer them counciling without public humiliation. I should add that repeat offenders should be identified so parents can be warned, but some of those guys on TCAP are just sad people who made a mistake and need help before they actually follow through with a heinous act.